Channel coding, such as forward error-correction coding or error-correction coding, introduces redundancy into a signal prior to transmission or storage of the signal. The redundancy enables a receiving system to detect and, perhaps, correct errors introduced into the signal by, for example, the channel, receiver, transmitter, storage medium, and the like. For example, in a communication system that employs forward error-correction coding, a source provides data to an encoder (also referred to as a coder). The encoder inserts redundant (also sometimes referred to as parity) bits, thereby outputting a longer sequence of code bits, called a codeword. The codewords can then be transmitted to a receiver, which uses a suitable decoder to extract the original, unencoded data and correct errors caused by, for example, the channel and/or the receiver.
Channel coding can thus be used to detect and/or correct errors—reducing the need for the source transmitter to retransmit data received in error. By reducing the need to retransmit data that is in error, the throughput of the channel or link is improved. Moreover, the correction of errors also improves the quality of the data received at the receiver. In the case of a digital video broadcast, error-correction coding enhances not only the quality of the digital video broadcast over the wireless channel but also improves the throughput of the wireless channel.